There are all sorts of groups that are looking for you. My favorite is Care Wear Volunteers. They knit for hosipitals and homes and publish a list of local organizations which are in need of donations.http://www.carewear.org/
The hospital list is on the upper right. You could see if you recognize one near you.

Don't forget domestic abuse shelters as well. And if you know someone else in your area that ships items to charities, maybe they'd let you throw in a blanket or two when they send. Won't make the shipping cost much more and increases what they can deliver.

And if you prefer that all your hard work not go to the dogs (and the cats), then try crises pregnancy centers, children's homes and hospitals, hospice care, shut-ins, and foster children.

You can also contact the churches around you and see if their ministries have a need for blankets. Or pick a disease (cancer, AIDS, MS, MD, etc.), find an organization that works with these patients, verify the organization's track record, and then contact them to see if they can use your blankets.

If you want to branch out and send your blankets around the world, pick a group to help: orphans in Bangladesh, rescued child soldiers in Africa, AIDS babies, rescued victims of human trafficking, etc., etc. Find an organization that helps these people, verify that organization's track record, and then contact them about your blankets.

The options are limitless! You might also check the following places for charity threads: Ravelry, crochet forums, and quilting forums.

Another alternative would be the Salvation Army. The Lutheran Church in America provides layettes to women in third world countries. Contact one of those churches in your area. You don't have to be a member. Many churches are also doing prayer shawls of all sizes and would be happy to accept your donations. Not only will you help people in your community but you will save on shipping costs. Bloom where you are planted is the old expression.